This is an application for a Core Center in Diabetes and Endocrinology. The purpose of the Core Center will be to provide a multidisciplinary approach to hormone action. The main theme will be the cellular and subcellular mechanism of action of insulin and insulin-like growth factors, but we also will study the mechanisms of action of steroid hormones and cyclic nucleotides, giving a comprehensive approach to hormone action. The Core Center will consist of several components. Core resources will include a tissue culture facility, a molecular biology segment, an administrative structure, and an enrichment program. We have proposed nine pilot and feasibility studies which relate to the Core Center theme, and which will use the Core Center Facilities. This Core Center will benefit our work in the following ways: 1) The multidisciplinary approach will afford us the talent and techniques required for the contemporary approach to hormone action; 2) The enrichment program and the communication through the Core facilities will lead to collaboration and hence increased productivity; 3) The Core resources will provide services not currently available, or will allow us to centralize many duplicated functions, 4) The Center will allow us, through the pilot studies, to test new ideas in insulin action, and to attract new investigators into this field.